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80 lines
2.3 KiB
80 lines
2.3 KiB
/* |
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* ADX ADPCM codecs |
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* Copyright (c) 2001,2003 BERO |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file |
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* SEGA CRI adx codecs. |
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* |
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* Reference documents: |
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* http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html |
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* adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/ |
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*/ |
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#ifndef AVCODEC_ADX_H |
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#define AVCODEC_ADX_H |
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#include <stdint.h> |
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#include "avcodec.h" |
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typedef struct ADXChannelState { |
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int s1,s2; |
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} ADXChannelState; |
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typedef struct ADXContext { |
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int channels; |
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ADXChannelState prev[2]; |
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int header_parsed; |
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int eof; |
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int cutoff; |
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int coeff[2]; |
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} ADXContext; |
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#define COEFF_BITS 12 |
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#define BLOCK_SIZE 18 |
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#define BLOCK_SAMPLES 32 |
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/** |
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* Calculate LPC coefficients based on cutoff frequency and sample rate. |
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* |
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* @param cutoff cutoff frequency |
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* @param sample_rate sample rate |
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* @param bits number of bits used to quantize coefficients |
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* @param[out] coeff 2 quantized LPC coefficients |
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*/ |
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void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff); |
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/** |
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* Decode ADX stream header. |
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* Sets avctx->channels and avctx->sample_rate. |
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* |
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* @param avctx codec context |
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* @param buf header data |
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* @param bufsize data size, should be at least 24 bytes |
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* @param[out] header_size size of ADX header |
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* @param[out] coeff 2 LPC coefficients, can be NULL |
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* @return data offset or negative error code if header is invalid |
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*/ |
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int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, |
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int bufsize, int *header_size, int *coeff); |
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#endif /* AVCODEC_ADX_H */
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